Good idea except for one little problem: the road to that boat ramp parking area ran below the dam, across the emergency spillway, and essentially no longer exists for a substantial portion of it. . . it washed away in the first few hours of the catastrophic failure. There is no way to truck rock, heavy equipment, etc., to that location. Perhaps they could boat them there?
You can see that road, or what’s left of it, in the photo that TXnMA posted just above.